Hydraulic jack



May 5 1935 E.' F..v GREEN 2,039,895

HYDRAULIC JACK Filed May 7', '1955 3 Sheets-Sheet 1 --g mm 7 E gweno #FL EE/V 47 #a lf I 43 E. F. GREEN HYDRAULIC JACK May 5, 1936.

Filed May 7, 1935 3 Sheets-Sheet 2 E. F. GREEN HYDRAULIC JACK May 5, 1936.

Filed May 7, 1935 3 Sheets-Sheet 3 Pne'nadvMay s, 193e y UNITED STATES .PATENT oFFiCE' urnaaumc .Tacx sm F. Green, denmark, r. Application May '1, 1935, Serial No. 20,186 s claims. (ci. 25a-z) My invention relates in general to hydraulic jacks and in particular to that type of jack having a pivoted power arm for raising automobiles, and known as garage or floor jacks. l

One of the objects of my invention has been to provide a jack having a release valve which is so designed that the oil passing by the same shall keep the valve and its seat clean.

'Another objecthas been to provide a :lack

having a release or lowering lever so located as to be within convenient reach of the operator but being so positioned that it will not be accidentally operated. Another object has been to provide a release control which shall be protected against accidental operation, said control being operable from the handle at any position of the handle.

- Another object has been to provide a jack having means. for locking the operating handle in 2o various positions.

Moreover, it has been an object to provide locking means which shall be retained in both their unlocked and locked positions.

Another object has been to provide a lack having a release valve which shall be can'ied by the cover of the reservoir, whereby release mechanism is'easlly accessible. Another object'has been to provide fa power unit for a jack of this type having the release valve arranged near the top of the cylinder,

whereby any entrained air will be readily discharged.

Moreover, my invention is of such nature that the power arm is directly connected to the power piston.

Furthermore, my device is provided with a baille plate mounted on the release valve which prevents oil returning from the lifting cylinder from impinging upon the valve stem packing or the 4o breather opening of the reservoir.

The above objects and advantages have been accomplished by the device shown in the accompanying drawings, oi. which:

Fig. 1 shows a perspective view of my complete device.

Fig. 2 is a thereof.

Fig. 3 is an enlarged, fragmentary. longitudinal, sectional view of the oil valve control mechnism.. taken on line 3 2 of Fig. 5. p Fig. 4 is an enlarged, fragmentary view partly in section, showing the handle locking mechanism and is taken on line 4-4 of Fig. 5.

Fig. 5 is a fragmentary, sectional. plan view taken on line 5 5 of Fig. 2. and also showing the longitudinal. sectional elevation operating handle with portions thereon broken away.

Fig. Gisasectionalviewtakenonlinet-l of nga.

Fig. 'l is a sectional view through one of the 5 swivel wheels and is taken on line 1-1 of Fig. 5. Fig. 8 is a detailed plan view of a portion of the side frame members.

Fig. 9 is a' fragmentary view of the upper section of the operating handle. 1o Fig. 10 isa fragmentary, sectional view of the oil reservoir iiller plug.

Fig. 1i is an enlarged, fragmentary, plan view of the. oil pump and connecting links.

Fig. 12 is a fragmentary, side view showing the 15 connections of the pull-back springs with the power arm.

My device comprises two side frame members I0 and Il which are held together preferably by a spacing arm I2 carried by each member and 20 securedtogether by means of a bolt I3. These spacing arms are arranged near the forward end of'the frame, and a spacing stud il is passed through suitable apertures in the frame members near therear end thereof and this stud carries a 25 spacing sleeve i5.

The power arm i8 of my device is pivotally secured between the side members lll and II of the frame at a point substantially midway their length and is designed to have its outer end mov- 30 able toward the forward end of the jack, as shown in dotted lines in Fig. 2. This power arm is mounted upon a pivot pin I'l which has its ends supported by the side members. This arm is of U-shape cross section and the lower end thereof 35 is provided with a propelling lever I8 which is reinforced by pads I8 extending from the pivot pin i1 of the arm to the pivot pin 20 carried by the propelling lever. The pivot pin 20, as shown in Fig. 2, is connected directly to the power pis- 40 ton 2|, to be hereinafter described. Pull-back springs 22 are provided. for the power arm. These springs have their forward ends preferabhr attached to the outer ends of the pivot pin 20 or to the cotter pins carried thereby, as clearly 4,5v

shown in Fig. 12. The other ends of the springs extend rearwardly and are preferably attached to the spacing stud ll and sleeve IB. g

At the upper end of the power arm is arranged a rest plate bearing 28 which is pivotally con- 50 nected at one side to the upper end of the power arm by means of the pivot pin 28. At a point on the opposite side of the bearing is provided a pivot pin 30 to which the upper ends of two drag links 3| are connected. The lower ends of these 55 drag links extend downwardly in substantial parallel relationship to the power arm and have their lower ends connected to the frame members by means of pivot pins or bolts 32. APivotally carried by the rest plate bearing is a rest plate 38. 'I'his rest plate, as is customary, is preferably pivotally carried by the bearing and has its upper face formed with a suitable depression 34 for non-slipping engagement with various parts of the chassis of an automobile.- y

The l.power unit 38 of my device is located preferably at the rear of the frame members and disposed therebetween. It comprises preferably a unitary casting which is pivotally suspended between the frame members upon a pivot pin 38. This unit is formed in its forward end with a power cylinder 48 having a bore 43 within which is slidably mounted the power piston 2|. The piston is provided on opposite sides with flattened surfaces 4| whichare arranged between and engaged with th'e propelling levers I8 through the pin 28, as hereinbefore pointed out. Theouter end of the cylinder is sealed'by means of a packing gland 42.

Formed in the power unit at the rear of the cylinder 48 is a pump cylinder 45 having a bore 48 within which is slidably mounted a pump plunger 41. A packing gland 48 is arranged at the outside of the cylinder for sealing the piston. The plunger 41 extends rearwardly toward the rear end of the device where it is provided with a plunger head 48. Passing transversely through the plunger head is a pivot pin 58. Attached at their outer ends to the ends of the pins 58 are two plunger links 5|. These links extend forwardly and are connected at their forward ends to downwardly extending operating arms 52 of the operating handle 53, to be hereinafter described.

Mounted above the cylinder 45 and at the rear of the power cylinder 48 is an oil reservoir .55 having a cover 5G. Connecting the beiei 45 of the pump cylinder 45 with the bore 48o! the power cylinder 48 are two passageways 51 and 58. These passageways are brought into communication by means of a vertical passageway 58 arranged above which is a ball check valve 68, held in place by a retaining plug 8|. Oil being forced from the pump cylinder 45 through the passage, way 51 will raise the check ball 88 and allow oil to be forced through passageway 58 into the power cylinder 48. Extending upwardly from the passageway 51 and into the oil reservoir is a passageway 62 which has a ball check valve 83 arranged at its lowerend and held in spm relation therewith by means of a retaining plug 84. Oil for the pump cylinder 45 is drawn through passageway 62 into the cylinder 45 through the passageway 51. Upon the return stroke of the plunger, the ball valve 68 is closed, thus forcing the oil, as just above described, into the power cylinder. Near the top of the bore 43 of the power cylinder 48 is arranged a valve plug 85 having a V-shaped seat 88 formed therein which is in communication with the cylinderthrough ports 61 and 88. A release valve stem 88 is mounted in the oil reservoir and has its forward end 18 pointed for engagement with the seat 88. The rear end 1| oi the valve stem is passed through a suitable aperture formed in the cover 56 of the reservoir where it is provided with suitable packing 12 of material such as felt. A washer 13 is arranged about the stem and disposed immediately in front of the packing, and a spacing sleeve 14 is also preferably mounted upon aosaaes the stem and in engagement with the washer. A washer 15 is disposed at the outside end of the sleeve and serves as an abutment for a helical spring 18, mounted on the stem and serving to force the pointed end thereof upon its seat. A 5 baille plate 11 is rigidly carried by the stem and disposed in iront of the spring so as to act as an abutment therefor. 'I'his baille plate is located near the valve plug 85 and is concave or dished on the surface which faces this plug, so that the oil coming through the ports 68 and 81 and passing by the pointed end 18 of the stem, will strike the baille plate and be deflected laterally from the stem,'thus prevmting the oil under pressure from striking the packing 13 or the opening 88 of the breather plug, to be hereinafter described, and possibly forcing its way therethrough. Carried by the cover 58 of the oil reservoir is a breather plug 81 which is provided with the centrai aperture 88 in which is mounted a plug of felt 88. When oil is being drawn from the reservoir or being discharged therein, air can pass into and out of the reservoir through this plug.

-Carried by the cover 58 of the oil reservoir is a release lever 88 having an outwardly extending arm 8| and a laterally extending arm 82. This lever is carried by a pin 88 attached to the reservoir cover. 'Ihe arm 82 of the lever is provided with a tapered opening through which the outer end 1| of the valve stem passes, suitable nuts 84 being carried by this end of the stem for engagement with the outer face of the arm 82 of the lever. The arm 8| of this lever extends rearwardly and downwardly 'andis provided at its extreme outer end with a curved portion 85. This curved portion has its face lying in a vertical plane and it -is preferably disposed. about the pivot pin 88 of the operating'handle 53, for reasons to be hereinafter described.'

'Ihe operating handle 58 of my device has a yoke 88 at its lower end which ispivota1ly carried by the pivot pin 88. 'I'he arms 52,'hreinbefore described, are made'a part of'this yoke. The operating handle is preferably made of two flat interspaced bars 8| which are secured by suitable bolts to the side of the yoke 88. 'Ihese bars -are attached at. their upper ends to a handle member 82. This handle member is provided with suitable handle grips 83 by which the handle may be conveniently manipulated, as well as providing means for elevating the forward end oi' the jack and moving it to the desired position. The handie member is provided at its under side with slots 84 in which is movable a finger grip 85. Extending outwardly through the center of the handle member and attached to the finger grip is a button 88. The button and ilnger grip are preferably held together by means of the screwthreaded upper end 81 of a control rod 88. This rod is preferably offset, as shown in Fig. 5, and it extends downwardly along the inside of one of the bars 8|. 'Ihe lower end of the contact rod 88 is provided with a right-angled bent portion 88 which is engaged with a locking plunger |88. This locking plunger is slidably mounted in suitable bearings |8| and |82 carried by the operating handle yoke 88. This locking plunger together with its associated parts forms the handie locking mechanism o! my device. The forward end |83 of the locking plunger, when the operating arm 53 is in the horizontal position, is engageable with a ledge |84 formed by a lug |85 carried by lthe power unit immediately in the rear of the reservoir.' When the operating handie is in its vertical position theend |83 of the 75 locking plunger will engage with a vertical surface |06 at the lower end of the lug |05. A number of holes ||l1 may also be provided in the arcuate face of the lug |05 for the engagement of the end |03 of the plunger when in any number of desired positions. .The bearing |0| for the locking plunger is preferably provided with a spring-pressed detent ball |08 which engages with either of two annular grooves |09 or ||0 formed in the locking plunger. As lshown in Fig. 4, when the groove I is engaged by the ball detent, the plunger is retained in its engaging position. whereas when the plunger is drawn backwardly by the finger grip 95 through the medium of the contact rod 9i, the plunger will -be held in its inoperable position. The nger grip 85 serves to draw the end |03 of the locking plunger out of engagement with the coasting surfaces lill and |06 and hole |01, and the button 96 serves to force the same into engagement therewith.

Pivotally mounted between the bars 9| of the operating'handle and upon a bolt |33 is a lowering lever which is .within convenient reach ofthe operator. This lever is provided with a serrated operating end ||2 which, as shown in Fig. 9. can only be reached by passing the linger in between the side bars 9| of the handle. This lever is provided with an upwardly extending arm Il! to which is pivotally attached a lowering rod lll. The lower end of the lowering rod is pivotally attached to the arm H5 of a release valve segment IIB. This segment is pivotally attached to the yoke by means of a pivot pin or bolt |32, and is provided with a forwardly extending arm ||1 which is formed on its extreme outer end with a pad H8. As hereinbefore pointed out, the surface of the curved portion 8i lies in a vertical plane and the pad III is, therefore, engageable with such curved portion 85 at any point in the operation of the operating handle 53. The release lever 80 is thereby operated by pressure upon the button ||2 of the lowering lever through the medium of the lowering rod ||8 and the release valve segment Hi.

'Ihe power cylinder 4l is preferably provided with safety means which prevent the jack from being operated to lift a load beyond the designed capacity thereof. These means preferably comprise a ball check valve.| I9 (see Fig. 5) which is pressed against a port |28 by means of astud |2| and a spring |22. A screw |23, carried by a lug |24, formed on the inside of the reservoir 55, bears against the opposite end of the spring. The port |20 is brought into communication with the bore I3 of the cylinder by means of a port |25.

The frame of my device is preferably provided with wheels I 26 at the forward end and with caster wheels |21 at a point near the rear end thereof. Each of the caster wheels is carried by a caster yoke |28 which is supported upon ball bearings |28 carried by the yoke and engageable with caster arm |30 carried at each side of thedevice.

A pump plunger guard |8| is preferably earried at the rear end of the device and mounted between the rear ends of the frame members Il and This guard covers the outer end of the pump plunger 41 together with the plunger head 49 and rear ends of the plunger links 5|.

From the foregoing, it will be clear that by pumping the operating handle up and down in any desired position and through any desired or necessary range, oil will be conducted from the reservoir and forced into the power cylinder I0 past the ball valves Il and 8l, as hereinbefore described. The power piston 25 will be moved forwardly in the cylinder 4l as oil is fed therein, and as it moves forwardly, it will cause the power arm and the vehicle carried thereby to be elevated the desired amount. When it is desired to lower the vehicle, the release valve stem 8! is moved axially ,through the release mechanism hereinbefore described and the oil is permitted to pass through ports Il and 81 of the valve plug' 85 and past the end 1I of the valve stem, whereby the oil will be conducted back to the reservoir. Since the angle formed by the vshaped seat 6l of the plug 6I is' preferably greater than the angle of the pointed end 1I of the release valve stem B9, the oil returning from the power cylinder to the reservoir, as just above described, will be forcedunder considerable pressure past the pointed end 10 of the valve and over the surface 88 of its seat and thus serve to keep this valve clean and in normal working condition. As hereinbefore pointed out, the oil entering the reservoir will be deflected by the baille plate 11 and thus prevent it from lmpinglns upon the packing 12 at the outer end of the stem or the breather plug.

Having thus described -my inventin, what I claim is:

l. A hydraulic jack comprising a frame, a power armpivotally carried by the frame, a power unit pivotally mounted in the frameand connected to the power arm, an operating handle pivotally attached to the frame and connected to the power unit, and locking means carried by thehandle, the power unit being formed with means, any one of which may be engaged by the locking means.

2. A hydraulic jack comprising a frame, a power arm pivotally carried by the frame, a power unit pivotally mounted in the frame and connected to the power arm, an operating handle pivotally attached to the frame and connected to the power unit, a locking plunger slidably carried by 'the handle, and actuating means carried by the handle and connected to the plunger, the power unit being formed with surfaces engageable with the plunger, whereby the operating handle may be locked in a number of various positions.

3. A hydraulic jack comprising a frame, a power arm pivotally carried by the frame, a power unit pivotally mounted in the frame and connected to the power arm, an operating handle pivotallv attached to the frame and connected to the power unit, a locking plunger slidably carried by the handle, actuating means carried by the handle and connected to the plunger, the power unit being formed with surfaces engageable with the plunger, whereby the operating handle may be locked in a number of various positions, and detent means for holding the plunger in its two extreme positions.

4. In a hydraulic vehicle jack, the combination with a wheeled frame, and a power arm pivotally carried by said frame, of a power unit comprising an integral casting pivotally mounted between the members of the frame, said casting being formed with a power cylinder opening at the forward end of the casting, a pump cylinder having Vits end opening at the rear end of the easting, a reservoir arranged behindthe cylinder and above a portion of the plunger, a power piston mounted in the power cylinder and connected to the power arm, said piston being movable toward the forward end of the device when raising the power arm, a plunger mounted in the pump cyl- 4 maar mia meuble towadtne rear ena or um vice when being moved outwardly in its cylinder.

- pivotaily mounted upon the trameior operating the pump plunger, valyed porta conv ncting the pump cylinder and the power cylinder with the reservoir and for connectingthepmnp -cylinder with the .power cylinder, acover toi-.the

reservoir. a release valve carried-bythe reservoir cover and having its tapered end engageable with the port connecting the reeervoir, and the power cylinder, and means for actuating the release valve. f f.

1 5. A lhydraulic Jack comprising a-two-part frame, each of the trame members being formed with an integral spacing arm extending towardthe opposite frame member, the inner endaot the .25 may beengaged by the locking means.

6. In a vehicle Jack,

tuating the release valve.

tion with'a wheeled frame, lund o. power ann pivotelly carried by said frame. of a power unit pivotally carriedby-the frame, -said'lmit being formed with a power cylinder opening at the foro! the unit.- a pump .cylinder having its end opening at the rear'endot the unit. a. i plunger-mounted in the pump cylinder and mov- I fable toward the rear end ot thedevice when-being moved 'outwardly in its cylinder. a reservoir arranked behind the cylinder and above a por- 1 tion of the plung'en'a power piston mounted in power cylinder and connected to the power s aid piston being movable-toward the forend oi.' the device when raising the power arm, means pivo mounted upon the frame [for operating the pump plunger, valved ports :connecting the pump cylinder and the power cylinder with the reservoir and for connecting Athe pump cylinder with the power cylinder, a -cover tor the reservoir, a release valve carried by the reservoir cover and having its tapered end l engageable .with the port connecting the reservoir and the power cylinder, and means for ac- EARL F. GREEN. 

